Pepper not herself today

Pepper will hardly eat her mid morning meal and is laying around a lot. Any suggestions on what I can try to entice her with to eat? Also, her Advantage II topical flea medicine is due today, should I apply it today or wait?

Update: I switched the flavor from Friskies Salmon Pate to Liver & Chicken Pate and heated it up for a few seconds in the microwave and she ATE IT! YAY! Now to hope she doesn't vomit. She went and laid back down.

But still wondering if I should wait on the Advantage Flea Medicine for a couple days.

Personally I would wait for the topical flea med. I would never dose an ailing cat with a topical flea med after what I went through with Leo and his reaction to Advantage. Probably one in a million reaction but Leo happened to be the one in a million.